f5de4f24b2
Instead of doing so in the constructor, let's do immediately after the constructor, so we can safely pass a reference of a Device, so the SysFSDeviceComponent constructor can use that object to identify whether it's a block device or a character device. This allows to us to not hold a device in SysFSDeviceComponent with a RefPtr. Also, we also call the before_removing method in both SlavePTY::unref and File::unref, so because Device has that method being overrided, it can ensure the device is removed always cleanly.
50 lines
898 B
C++
50 lines
898 B
C++
/*
|
|
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
|
|
*
|
|
* SPDX-License-Identifier: BSD-2-Clause
|
|
*/
|
|
|
|
#include <AK/Singleton.h>
|
|
#include <Kernel/Devices/NullDevice.h>
|
|
#include <Kernel/Sections.h>
|
|
|
|
namespace Kernel {
|
|
|
|
static Singleton<NullDevice> s_the;
|
|
|
|
UNMAP_AFTER_INIT void NullDevice::initialize()
|
|
{
|
|
s_the.ensure_instance();
|
|
s_the->after_inserting();
|
|
}
|
|
|
|
NullDevice& NullDevice::the()
|
|
{
|
|
return *s_the;
|
|
}
|
|
|
|
UNMAP_AFTER_INIT NullDevice::NullDevice()
|
|
: CharacterDevice(1, 3)
|
|
{
|
|
}
|
|
|
|
UNMAP_AFTER_INIT NullDevice::~NullDevice()
|
|
{
|
|
}
|
|
|
|
bool NullDevice::can_read(const OpenFileDescription&, size_t) const
|
|
{
|
|
return true;
|
|
}
|
|
|
|
KResultOr<size_t> NullDevice::read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
KResultOr<size_t> NullDevice::write(OpenFileDescription&, u64, const UserOrKernelBuffer&, size_t buffer_size)
|
|
{
|
|
return buffer_size;
|
|
}
|
|
|
|
}
|